Traffic barricades are commonly used to warn vehicular and pedestrian traffic of danger, and block off restricted areas. Barricades made of molded plastic have now been known for some time. Examples are found in the Stehle, et al. U.S. Pat. Nos. 3,880,406 and 3,950,873, the Glass U.S. Pat. Nos. 4,298,186 and 4,624,210. Barricades illustrated in these patents include barricades made with two panel units hinged together so that they can be spread apart for use and collapsed for storage or transport. The individual panel units are one piece, integral, hollow plastic panels, formed by rotational or blow molding. The lower hollow sections may contain ballast.
These and other plastic traffic barricades have proven to be a great improvement over conventional steel and wood barricades. They are rugged, yet cause less damage to vehicles if inadvertently struck. Through the use of ballast in the units, the center of gravity of the barricade is lower than either wood or metal barricades. The result is a barricade less susceptible to being blown over by wind. Other features typically incorporated in such barricades are bright colored reflective horizontal panels, flashing lights or signs, and a structural member near the bottom where a sand bag can be placed if additional ballast is required.
Problems linger with many plastic barricades on the market today, however. Internally ballasted plastic barricades have proven to be marginally acceptable on high speed highways because they are not heavy enough to remain in place when buffeted by vehicle induced drafts. All to frequently, on the other hand, externally ballasted barricades deform under the weight of sandbags. When barricade assemblies are struck by a moving vehicle, for example, their structural integrity also leaves something to be desired. When components are damaged, they cannot be readily cannibalized for use in other barricade assemblies. Many of them are not sufficiently compact to permit stacking large quantities of assembled barricades together for transport.